Flow meter



Dec, 16, 1924.

W. J. A. LONDON FLOW METER Filed Nov. 25. 1925 nvmvro Julio/24 k,

I'd/r1 A TTORNE Y.

' where Wzweight of steam in discharge in I Patented Dec. 16,1924.

mm STATES suisss PATENT OFFHZE.

rnow mart n.

Application filed November To all whom it may concern:

Be it known that I, WILLIAM J. A- LON- noN, a-subject of the King of Great Britain, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful Improve ments in Flow Meters, of which the following is a specification. v

This invention relates to improvements in flow meters.

It is designed for use as for example with steam turbines or other apparatus where steam or other gaseous fluids is expanded through; nozzles and where the, terminal pressure at the end of the nozzles is less than approximately .58 of the initialpressure.

An object of the invention is to combine with the ordinary steam' pressure gage, a movable member'having. numerals or figures thereon which indicate the area of the noz-- zle' through which the steam flows, and, a compensating mechanism between the point- 1 er of the gage and the usual Bourdon tube,

whereby the movements of the pointer, in-- stead of being uniform throughout its travel will correspond with the various adjusted positions of the movabledial on which the nozzle areas are placed. The well-known Napiers formula for the flow of steam through nozzles furnishes a very accurate method of computin the flow of steam. The formula is as fol ows:

pounds per second, P=absolute pressure in pounds per-square inches. A'znozzle area at'the throat in square inches.

This formula has been carefully checked up'by many thousands of experiments and in general steam turbine practice it is acceptedas being theoretically correct except that in practice it is found that the constant 7 O should be changed to 72 as giving a closer approximation of the steam flow in pounds per second than Napiers original constant 70.

The flow of steam oer second would be too small a time to measure the weight, therefore, the formula should be changed to read or measure the flow of steam per hour, and

- usin the 'constant 7 instead of 70. the urea as, 1923. Serial at. 676,655.

eutformula of flow of steam per hour in pounds is pressure gage may be usedto measure the fiow of steam when placed at the inletof the, nozzle if the pressure registered is-multiphed by the area of the jet and divided by the constant.

An ordinary steam gage may therefore be used as a steam flow meter.

The only change in the ordinary steam gage would therefore be the attaching of a dial.v which would read directly the flow of steam in pounds passing through nozzles of different sizes, and which may be adjusted to suit nozzles ofdifi'erent areas. To obtain results for different pressures. a compensating mechanism between the pointer of the pres-n.

sure gage and the Bourdon tube would be necessary whereby. the pressure-and: weight of flow of steamis notrecorded' in equal increments but is recordedon a logarithmic scale. V l Referring'to the drawings:

Fig. 1 isa front elevational view, of the instrument showing figures indicating steam pressure, a movable dial with figures there-I- nozzle area in square inches and'a pointer member which is actuated by the ordinary Bourdon tube.

- I Fig. 2 is a verticalsectional'view on the line 2-2 of Fig. 1, showing the compensating' gears between the Bourdon tube and "the pointer, also a movable dial, the pointer.

.-.having one portion which swings over the zmovable. dial and the other portion which moves over the fixed dial for indicating steam pressures.

ing gears between the tube and the pointer.

Referring to the drawings in detail:

1 designates the usual steam gage cas-- ing ha ing a pipe 2 for attaching the gage to a steam pipe. 3 is the usual Bourdon tube one end of which is in communication with the pipe 2 and its free .end .4 being conneoted to the gear-Shy means of the link 6. This gear is pivoted to the casing at. the

Fig. 3 is a vertical sectional view on the i line 3- -3 of Fig. 2 showing the compensat- 'way. On the point 7. -S desigiiates a gear meshing'with the gear the'teeth of. these gears are laid out on what is known as the'logarithmic spiral for the purpose of imparting a comp pensating movement to the pointer 9. This pointer is formed with a downwardly extending portion and an upwardly extending end 11. The end 10 swings over the a movable dial 12' and the end 11 swings oyer the dial 13 which is secured to the casing by means of the bracket 14: .or other suitable dial 13 is placed the nu morals, 50, 100, 150, 200', etc.,.-representing pigessures in pounds per square inch.

hplticed that the spacing of these'numerals e lines 15 is not equal but are laid out I with the logarithmic scale. 12 are, placed the numbers in accordance On the dial 2500, 5000, 7500, 10,000, etc.,' which indicates steam per hour,

the weight in pounds of flowing through nozzles of difierent areas casing 1 and is located adjacent the divispacing which turns in an opening of the glasstront and to which the-dial 12 iS Secured 8.811161- The' instrument is.

cated by the pin 20. used as follows:

The operator turns the dial 12 'bymea'ns of the knob 21 so that the pointer 17 correspendswith the correct nozzle area as indicated by the numeralsLOO, 1.25, 1.50, etc.,-

which is 1 the correct nozzle area through which the steam or other gaseous fluid is flowing. As for example, it the steam pressure is 100 lbs. absolute, and the nozzle-area is. 1 square inch, the flow-of steam per hour would be indicated by the pointer as 5,000. lbs. which numer-*l .as shown in Fig. l is opposite the numeral 100 that ,represents order to mail the instrument read steam pressure. If the nozzle-"area is 2 square inches and the dial 112' is turned so that the pointer 17 is opposite 2 square inchesand the pressure i still'lOO the flow of steam in pound per hour would then be. 10,000 as indie in dotted lines and in accurately the logar'thmic or compensating gears 5 and 8 are emiloyed to make the throw of the pointer 9- rrespond with the logarithmic reading of the steam pressures and weights or'fiow of steam per hour as indi rated on the dial 12.- 1

It will therefore be seen from this descriptionthat a ordinarysteam pressure gage may readil of steam. in pounds per hour correspon to steam nozzles of differ- It will be used'so as to directly.

ent areas and ditierent boiler pressures. It

being understood that the. pressures 'computed are absolute pressures. It is also apthe variation is beyond the practical scope of one dial.

arent that separate dials can be fitted where v It is to be understood that the present invention is not intended to be limited to. measuring the. flow of steam. in pounds per hour but is intended ior general application wherever. occasion arises for the use of such instruments, as the measurement of the flow of air or other gaseous fluids, in pounds per hour. 4 I What-Iclaimis:'

1. In a fluid flow meter, the combination, of a dial to indicate 'pr'es'suresfof the fluid, ass'team, a movable dial for indicating the weight of the flow of the fluid. perhour and having thereon a-series of eating the nozzle area in square'j inchesand figures for'mdiother. figures for indicating thewei ht of:

the fluid, a Bourdon tube, a pointer a apted to swing over both scales of -thedials therea on, a compensating. mechamsm'between the pointer and the Bourdon tube, whereby the pointer will simultaneously fluid pressure and the of a fixed dial having numerals thereonfor indicatingthe pressures of the fluid-to be measured and spaced from each other in accordance with the logarithmic scale, a movable dial having-ynumerals/thereonfor indicating the flow of the fluid p'er hour and spaced from each other in accordance with the spacing of the pressure indicating numerals, said movabledial having numerals designate the fiowof the fluid per hour corresponding tonozzles of different areas.

- 05 2. In a fluid flow meter, the combination thereon indicatingthe area of'thenozzle in square inches, a pointer secured 'to the casing and designed to re ister with the movable dial having numera overthe two dials and acompensatingdethereon which. designate nozzle areas, a pointer adapted to swing vice' for controlling the movements of the pointerin accordance with the'spacing ofthe dials. a

3. A combined pressure and fluid flow in strument comprising, in combination, aneuclosing casing, a fluid reeeiving tube there- H in, a movable pointer, compensating devices between the pointer and tube and including gears formed as, logarithmic spirals, two

dials,- one being fixed and the other movable having numerals thereon for'i11dicating.tli e' flUAdXI'BSSHY B and-flow respectively. 4. =eombmatron fluid pressure gage-rand flow, meter com'rising, 1n combination, 'a pointer, two 'dia s, one dial being fixed and the other movable and ,over whiohl the pointer moves, the movable dialhayin'ggipumerals thereon for. indicating nozzle 1 of different sizes and the flow .dfltliee fluid I for each nozzle area, the casing having a pointer secured thereto for cooperating with said movable dial and area numerals for determining the position of the movable dial 5 and compensating means for actuating the moivable pointer in accordance with the spacing of the numerals on the fixed and movable dial to simultaneously indicate fluid pressures and the flowof the fluid in 10 pounds per hour with reference to a particu lar nozzle area.

5; An instrument for the purpose de scribed, including a movable pointer a fixed and a movable dial having graduations thereon which are spaced from each other 15 in accordance with the logarithmic scale, and numerals adjacent the spacing to indicate pressures and flow of a. fiuidas steam or air, and means comprising gears form as logarithmlc spirals for actuating the 20 W pointer in accordance with the s acin WILLIAM J. A. LO DO 

